Sometime there is necessity to drive nails into totally unsuitable surface of timber (for example bamboo, yes, I know it sound ridiculous, but not everyone live in north america.), it is then good idea to spray nails with teflon or silicone oils, This treatment allow penetration even in bamboo, mahagony and other timbers harder than 12 in Jenkins scale without riping them apart.
If nail takes 'dive' and is more than thickness of the head below the surface, you need to decrease the pressure till you achieve this 'golden' level of flush or just below the surface. If nail stick above the surface, you need increase pressure (in stages! Do not jump from one extremity to another!), till you achieve flash suurface. You know that pressure is correct to material when nail head is flushed with surface of the timber or very slightly below. Setting depend on several variables, that is thickness of the timber, hardness of the timber, lenght of the nail, to certain extend hardness and diameter of the nail. Framers operate, depending on the brand, on 45psi (2.5bar) to 120psi (8.3bar). You did not provide brand, but this broad spectrum will give you some indication.
